Silicone-coated mineral wool insulation materials and methods for making and using them

ABSTRACT

The present disclosure relates to silicone-coated mineral wool insulation materials, methods for making them using specific coating methods, and methods for using them. One aspect of the disclosure is a method for making a silicone-coated mineral wool, the method comprising: providing a mineral wool comprising a collection of mineral wool fibers; applying to the mineral wool a solvent-borne coating composition comprising a silicone, the silicone of the coating composition having a number-average molecular weight of at least 25 kDa; and allowing the solvent to evaporate to provide silicone-coated mineral wool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 62/658547, filed Apr. 16, 2018, which is herebyincorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates generally to insulation materials andmethods for making and using them. The present disclosure relates moreparticularly to silicone-coated mineral wool insulation materials,methods for making them using specific coating methods, and methods forusing them.

2. Technical Background

Insulation materials such as mineral wool batts, rolls and blankets aretypically used to reduce the rate of heat transfer between two areasseparated by a boundary. For example, in an attic, insulation materialcan be applied to the interior surface of the roof deck to slow thetransfer of heat through the roof deck, that is, from the exterior ofthe house to the attic or vice versa. In another application, insulationmaterial is applied to exterior walls (e.g., between wood studs) andcovered with wallboards to slow the rate of heat transfer through theexterior wall and the wallboard. Insulation material can also preventundesirable air movement (e.g., convection drafts) and resultantmovement of moisture from one space to another.

Mineral wool insulation materials are often formed in mat-likestructures, with individual fibers being bound together in a non-wovenstructure by a binder. Such materials can be provided in the form of,e.g., blankets, batts or rolls, which can be disposed against buildingsurfaces to insulate them. Such materials are typically disposed inattics (e.g., against a ceiling or a floor) or within walls to provideinsulation.

More recently, the use of blowing wool or loose-fill insulation hasincreased in popularity. Loose-fill insulation is typically made upchiefly of non-bonded short mineral wool fibers, typically treated withadditives such as dedusting oils and antistatic compounds. Loose-fillinsulation is typically compressed and packaged into bags. Installationis performed (e.g., into attics and sidewalls) using a pneumatic blowingmachine; the blowing process desirably uncompresses the loose-fillinsulation to provide it with a desired low density.

Loose-fill insulation is popular with insulation contractors because itcan be easily and quickly applied in both new construction as well as inexisting structures. Further, loose-fill insulation is a relativelylow-cost material, and has lower labor costs to install as compared tomaterials in the form of batts, blankets and rolls. However, loose-fillinsulation is typically applied by contractors rather than homeownersbecause of the special blowing equipment needed. Such insulation istypically packaged in large bags weighing, e.g., 20-40 lbs.

When loose-fill insulations are pneumatically applied, they can be thesource of dust and irritation for the installer. While deducting oilsare typically applied at the time of manufacture to control this dust,and the installers are advised to wear a dust mask and protective gearto reduce their exposure to dust, the effectiveness of these oils couldbe improved, especially when the oils are applied at low applicationrates (e.g., less than about 2% by weight).

Silicones are often applied to the fibers of mineral wool insulationmaterials. One reason to do so is to improve fiber-to-fiber lubricity.In loose-fill insulation, this helps the materials to decompress duringblowing to provide a material having a relatively low density, and thusa relatively high area of coverage per unit weight. Silicone coatingsalso render the fiber surfaces hydrophobic, to help prevent waterabsorption and to protect the mineral material from hydrolytic attack.

But improvements in mineral wool insulation materials are still needed.

SUMMARY OF THE DISCLOSURE

One aspect of the disclosure is a method for making a silicone-coatedmineral wool, the method comprising:

-   -   providing a mineral wool comprising a collection of mineral        fibers:    -   applying to the mineral wool a solvent-borne coating composition        comprising a silicone, the silicone of the coating composition        having a number-average molecular weight of at least 20 kDa        (e.g., at least 25 kDa); and    -   allowing the solvent to evaporate to provide silicone-coated        mineral wool.

Another aspect of the disclosure is a silicone-coated mineral wool madeby a method as described herein.

Another aspect of the disclosure is a silicone-coated mineral woolcomprising a mineral wool comprising collection of mineral wool fibershaving a silicone coating comprising a silicone having a number averagemolecular weight of at least 20 kDa (e.g., at least 25 kDa).

Another aspect of the disclosure is an insulated structure having aninterior surface (e.g., a surface of a wall, a ceiling, floor, an attic,a basement, or another building surface), and a silicone-coated mineralwool as described herein disposed against the interior surface.

Another aspect of the disclosure is an insulated structure having aninterior surface and an exterior surface, and a silicone-coated mineralwool as described herein disposed in a space (e.g., partially orsubstantially filling the space) between the interior surface and theexterior surface.

Another aspect of the disclosure is an insulated cavity having a firstsurface and a second surface, and a silicone-coated mineral wool asdescribed herein disposed in between the first surface and the secondsurface.

Additional aspects of the disclosure will be evident from the disclosureherein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the methods and devices of the disclosure, and areincorporated in and constitute a part of this specification. Thedrawings are not necessarily to scale, and sizes of various elements maybe distorted for clarity. The drawings illustrate one or moreembodiment(s) of the disclosure, and together with the description serveto explain the principles and operation of the disclosure.

FIG. 1 is a bar graph showing measured peak molecular weights forvarious silicone materials.

FIG. 2 is a schematic view of an insulated structure according to oneembodiment of the disclosure,

FIG. 3 is a schematic view of an insulated structure according toanother embodiment of the disclosure.

DETAILED DESCRIPTION

As noted above, mineral wool materials are conventionally coated with asilicone in order to improve inter-fiber lubricity and provide thefibers with hydrophobic surfaces to help prevent moisture absorption bythe material and to protect the fibers from hydrolytic attack.Conventionally, this coating is performed using an aqueous emulsion of arelatively low-molecular weight silicone, applied while the fibrousmaterial is still hot from being spun or drawn from bulk material.Conventional silicones used for such purposes include, for example,silicones having a number-average molecular weight in the range of 10-15kDa, e.g., Dow Corning DC 346 and Wacker Chemie BS1052.

The present inventors have unexpectedly determined that conventionalsilicone coating processes provide coated materials that suffer from areduction in beneficial properties, especially during the first hourafter coating. The present inventors have determined that the use of ahigh-molecular weight silicone can address the problem of siliconebreakdown. Again, without intending to be bound by theory, the inventorssurmise that such high-molecular weight silicones can undergo breakdownwith roughly the same kinetics as the low-molecular weight silicones.But, critically, the resulting breakdown products would be of muchhigher molecular weight than those in the low molecular weight siliconecase, and thus can be retained as a higher-quality coating on thefibers.

Accordingly, one aspect of the disclosure is a method for making asilicone-coated mineral wool material. The method includes providing amineral wool comprising a collection of fibers; applying to the mineralwool a solvent-borne coating composition comprising a silicone; andallowing the solvent to evaporate to provide silicone-coated mineralwool. Notably, the silicone of the solvent-borne coating composition hasa number-average molecular weight of at least 20 kDa, The mineral woolmaterials made by such processes can be especially useful as insulationmaterials, for example, as loose-fill insulation materials.

As the person of ordinary skill in the art will appreciate, the mineralwool can be made from a variety of materials. For example, in certainembodiments as otherwise described herein, the mineral wool is a glasswool. Glass wools can be made from a wide variety of glasses. forexample, silicate glasses such as borosilicate glasses. aluminosilicateglasses and aluminoborosilicate glasses. Glass wools are frequentlyreferred to as “fiberglass” in the art. In other embodiments, themineral wool is a stone wool (also known as a rock wool), or a slagwool.

The fibers of the mineral wool are desirably relatively fine, so as toprovide materials that can be installed by blowing to provide arelatively low density, and therefore a relatively high degree ofinsulation. Thus, in certain embodiments as otherwise described herein,the median diameter of the fibers of the mineral wool (i.e., taken foreach fiber as the maximum distance across the fiber in a directionperpendicular to the length of the fiber) is no more than about 100microns, e.g., no more than about 50 microns or even no more than about20 microns. While relatively fine fibers are desired, in certainembodiments it is desirable for the fibers not to be too thin, so as notto create an inhalation hazard. Accordingly, in certain embodiments asotherwise described herein, the median diameter of the fibers of themineral wool is at least 500 nm, e.g., at least 1 micron or at least twomicrons. The lengths of the fibers will vary, for example, depending onthe desired end use of the material. In certain embodiments as otherwisedescribed herein, the median length of the collection of fibers is nomore than 500 mm, e.g., no more than 250 mm, or no more than 100 mm. Forexample, fibers made for use as loose-fill insulation will generally berelatively short. In certain embodiments, the median length of thecollection of fibers is no more than 50 mm, e.g., no more than 25 mm, oreven no more than 10 mm.

The mineral wool itself can be made using conventional methods, from anumber of different materials, e.g., glass, rock or stone (e.g., basaltor diabase, or other volcanic or subvolcanic rock), an at leastpartially purified mineral, slag, or a mixture thereof. Typically, themineral source is molten and formed into fibers, using any of a numberof spinning, centrifugation, drawing, or other fiberizing processes. Thefiberizing process itself can provide fibers of a desired length, orfibers can be chopped to a desired size. The resulting hot mineralfibers can then discharged from the fiberization apparatus and allowedto cool as one or more coatings or other treatments (including thesilicones described herein) are applied thereto: the application of suchcoatings/treatments can help to cool down the hot mineral fibers. Thecooled fibers can be collected, further treated if desired, and thenpackaged.

Silicones can be added while the fibers are still relatively hot, suchthat the solvent of the solvent-borne silicone can evaporate to helpcool the fibers and to form the silicone coating as a layer of siliconeon the surfaces of the fibers. The person of ordinary skill in the artwill appreciate that the layer of silicone, especially when formed fromdroplets in a spray, may not be of a single uniform thickness, butrather may have significant variations in thickness and coverage onindividual fibers and even on different areas of individual filers.Nonetheless, the amount of silicone on a collection of fibers can becharacterized by an overall amount of silicone as a wt % of overallfiber mass. In certain embodiments as otherwise described herein, themineral wool is at a temperature in range of 200-500° C. when it iscoated with the solvent-borne coating composition. In certain suchembodiments, the mineral wool is at a temperature in the range of200-465° C., or 200-430° C., or 240-500° C., or 240-465° C., or 240-430°C., or 285-500° C., or 285-465° C., or 285-430° C. when it is coatedwith the solvent-borne coating composition. Upon coating, the solvent ofthe coating composition can begin to evaporate; this, along with thegenerally cooler temperature of the coating composition, can serve tocool the mineral wool and dry the silicone coating on the fibers of themineral wool. Optionally, the mineral wool can be cooled somewhat (e.g.,by spraying of a mist of water) before the application of the coatingcomposition, in order to bring the mineral wool to a desired temperaturefor application of silicone, Upon application of the coatingcomposition, evaporation of much of the solvent and the generally lowertemperature of the coating composition can lower the temperature of thefibers, e.g., to a temperature in the range of 50° C. to 250° C. Thus,while the fibers are not as hot as they were before coating, they canstill be still relatively hot.

Without intending to be bound by theory, the inventors surmise that thesurface acidity/basicity of the mineral wool fibers is one importantfactor in the determination of ultimate material properties, especiallydue to the fact that the fibers typically remain relatively hot for sometime after application of the silicone. Accordingly, in certainembodiments as otherwise described herein, the mineral wool (i.e.,before being coated by the silicone) has a high surface basicity.Surface basicity can be determined by collecting the mineral wool (i.e.,at the point in the process at which it is to be coated by thesilicone), allowing it to cool, and performing the following pH soaktest: The mineral wool (50 g) is combined with 1000 g of deionized waterin a plastic jug. The jug is capped and shaken vigorously for 30seconds. The glass wool sample is squeezed to drain any fluid into thejug, then liquid from the jug is filtered into a 250 mL beaker and thepH of the filtrate is measured using a pH meter to provide a soak testpH. In certain embodiments as otherwise described herein, the mineralwool has a soak test pH in the range of 8 to 11 just before it iscoated. In certain such embodiments, the mineral wool has a soak test pHin the range of 8.5-11, or 8.5-10.5, or 8.5-10, or 9-11, or 9-10.5, or9-10.

As described above, the present inventors have determined that it can beadvantageous to use a high-molecular weight silicone in the coating ofmineral wool fibers, especially at the temperatures and/or surfacebasicities described herein. Accordingly, in certain aspects of thedisclosure, the silicone of the coating composition has a number-averagemolecular weight of at least 20 kDa, In certain embodiments as otherwisedescribed herein, the silicone of the coating composition has anumber-average molecular weight of at least 25 kDa, or at least 30 kDa,or at least 40 kDa, or at least 50 kDa, or at least 60 kDa. The personof ordinary skill in the art will understand that a variety of highmolecular weight materials can be used, as long as they can beeffectively coated from a solvent-borne coating composition.

A variety of silicones can be used in the methods and materialsdescribed herein. For example, in certain embodiments, the silicone is apolysiloxane, e.g., a polymer or copolymer of one or more of analkylsiloxane such as dimethylsiloxane and methylsiloxane; andarylsiloxane such as phenylmethylsiloxane, 2-phenylpropylmethylsiloxane,and phenylsiloxane; and a functionalized siloxane such as3-aminopropylmethylsiloxane, and aminoethylaminopropylmethoxysiloxane.In certain embodiments, the silicone is a poly(dimethylsiloxane). Thesilicone can be terminated in any convenient way, e.g., trimethylsilyl,hydroxy, or hydride.

The solvent-borne coating composition can be provided in a variety offorms, e.g., as an emulsion of the silicone in the solvent, or as asolution of the silicone in the solvent. (That is, the solvent need notactually dissolve the silicone; rather, it merely needs to provide anevaporable liquid carrier for the silicone.) In certain desirableembodiments, the solvent of the solvent-borne coating composition is anaqueous fluid, e.g., water. Water is environmentally benign, has a highheat capacity and heat of vaporization (and so provides efficientcooling of the hot mineral fibers), is not flammable, and is the basefor many commercial silicone dispersions. But in some cases othersolvents can be used. The concentration of the silicone in the coatingcomposition can be, for example, in the range of 0.01-5% by weight. Incertain embodiments, the concentration of the silicone in the coatingcomposition is in the range of 0.01-5%, or 0.01-3%, or 0.01-2%, or0.01-1%, or 0.01-0.5%, or 0.05-5%, or 0.05-3%, or 0.05-2%, or 0.05-1%,or 0.05-0.5%, or 0.1-5%, or 0.1-3%, or 0.1-2%, or 0.1-1%, or 0.1-0.5%.

Conventional coating methods can be used to apply the coatingcomposition to the mineral wool. For example, in many conventionalmanufacturing methods, the fibers are formed then fall verticallythrough a cooling zone to be collected; the coating composition can besprayed on the fibers of the mineral wool as they fall. The rate ofspraying can be adjusted with respect to the rate of formation of thefibers to provide a desired amount of coating on the fibers. Of course,other application methods can be used. The rate of application (e.g.,via spray) of the coating composition to the mineral wool (i.e., theamount that is conducted to the mineral wool, including any systemlosses) can be, for example, in the range of 0.1-10 mg silicone per grammineral wool, e.g., in the range of 0.1-5, or 0.1-3, or 0.1-2, or 0.1-1,or 0.2-10, or 0.2-5, or 0.2-3, or 0.2-2, or 0.2-1, or 0.5-10, or 0.5-5,or 0.5-3, or 0.5-2 mg silicone per gram mineral wool.

The person of ordinary skill in the art will appreciate that not all ofthe silicone in the applied coating composition will initially beretained on the fibers; there are typically system losses that causesome fraction of the coating composition not to be picked up by thefibers. The amount of silicone on the fibers after spraying can incertain embodiments be, for example, in the range of 0.1-10 mg siliconeper gram mineral wool, e.g., in the range of 0.1-5, or 0.1-3, or 0.1-2,or 0.1-1, or 0.2-10, or 0.2-5, or 0.2-3, or 0.2-2, or 0.2-1, or 0.5-10,or 0.5-5, or 0.5-3, or 0.5-2 mg silicone per gram mineral wool.

Once the coating composition is applied, the solvent is allowed toevaporate to provide a silicone-coated mineral wool. The person ofordinary skill in the art will appreciate that in many systems, noespecial arrangements need be made to evaporate the solvent; thetemperature of the mineral wool at the time of coating, the temperatureotherwise in the system, and flow of air or other process gas throughthe device is sufficient to evaporate the solvent. Of course, in otherembodiments, the silicone-coated mineral wool can be heated or subjectedto a flow of air or other process gas in order to evaporate the solvent.The silicone-coated mineral wool can be collected on, e.g., a conveyeras is conventional in the art.

The person of ordinary skill in the art will appreciate that a varietyof other materials can be applied to the mineral wool. For example, anantistatic additive, such as a quaternary ammonium salt, can be appliedto the mineral wool (e.g., by spray application from aqueous solution),in an amount effective to prevent static buildup in the final product.

Similarly, in many embodiments, a dedusting oil (e.g., a bright stockoil) can be applied to suppress dust in the final product. Oil can beprovided, for example, in an amount within the range of 0.5-4% by weightof the mineral wool, e.g., about 2%. Conventional oils can be used,e.g., Telura™ 720E or Prorex 100 from Exxon-Mobil. A small amount (e.g.,about 2% by weight) of surfactant (e.g., nonionic or cationic, such as amono-, di- or tri-fatty acid ester) can be included in the oil.

The person of ordinary skill in the art will appreciate that these andother additional materials can be applied to the mineral wool in anydesirable order. For example, in one embodiment, an antistatic additiveis applied to the mineral wool after the silicone-containing compositionis applied, and while the mineral wool is still warm, with the oil beingapplied after the mineral wool has cooled. But other embodiments arepossible. In certain embodiments, one or more of these and otheradditional materials are applied at the same time as thesilicone-containing coating composition (e.g., by being mixed into thesilicone-containing coating composition, or by being applied at the sametime as the silicone-containing coating composition). However, in otherembodiments, substantially no other material is applied together withthe silicone (i.e., the silicone-containing coating composition consistsessentially of the silicone and the solvent).

In certain embodiments, the silicone-coated mineral wool is formed as anunbound loose-fill material, i.e., substantially no binder is applied tothe silicone-coated mineral wool mineral wool. Such a material can beprovided as relatively short fibers, suitable for installation usingconventional loose-fill installation methods, e.g., by being blownthrough a hose for disposition against an interior surface of abuilding.

The silicone-coated mineral wool materials described herein can bepackaged, e.g., by being compressed and packaged, e.g., into bags orother sealed containers.

Another aspect of the disclosure is a silicone-coated mineral wool madeby a process as described herein.

Another aspect of the disclosure is a silicone-coated mineral woolcomprising a mineral wool comprising collection of mineral wool fibershaving a silicone coating comprising a silicone having a number averagemolecular weight of at least 20 kDa. The molecular weight of thesilicone can be determined through matrix-assisted laser desorptionionization-time of flight secondary ion mass spectrometry (MALDI-TOFSIMS), In certain such embodiments, the silicone has a number-averagemolecular weight of at least 25 kDa, for example, at least 30 kDa, or atleast 40 kDa, or at least 50 kDa, or at least 60 kDa, or at least 70kDa. The molecular weight of the silicone used in the manufacture ofsuch a mineral wool can be selected to provide the final product with acoating silicone having such molecular weights, taking into account aparticular mineral material and manufacturing process. The use of ahigh-molecular weight silicone in the coating composition can providesilicone coatings of a substantially higher molecular weight, and thus asubstantially higher quality than the conventional use oflower-molecular weight silicones.

The silicone-coated mineral wool according to this aspect of thedisclosure can otherwise be substantially as described above withrespect to the methods described above. And, in certain embodiments, thesilicone-coated mineral wool according to this aspect of the disclosurecan be made by a method as described herein,

The silicone-coated mineral wool materials described herein can beprovided with a variety of densities, depending on the desired end use,For example, for use as insulation materials, the silicone-coatedmineral wool materials can in some embodiments be provided withdensities in the range of 0.1-20 lb/ft³. In various embodiments, thesilicone-coated mineral wool material has a density in the range of0.25-8 lb/ft³ (e.g., with the mineral wool being a glass wool); or0.25-2 lb/ft³ (e.g., with the mineral wool being in the form of aflexible building insulation material); or 0.25-0,75 lb/ft³ (e.g., withthe mineral wool being in the form of a flexible highly compressiblebuilding insulations); or 0.25-0.510 lb/ft³ (e.g., with the mineral woolbeing in the form of a loose-fill insulation).

The mineral wool materials described herein can advantageously be usedas insulation materials in a variety of contexts, including insulationof building structures. Accordingly, another aspect of the disclosure isan insulated structure, the insulated structure having an interiorsurface (e.g., a surface of a wall, a ceiling, floor, an attic, abasement, or another building surface), and a silicone-coated mineralwool as described herein disposed against the interior surface. One suchembodiment is shown in FIG. 2. Here, the insulated structure is house200, of which an attic section is shown in detail. The interior surfaceis a ceiling surface 210 facing an attic 220, with a silicone-coatedmineral wool 230 as described herein disposed against the interiorsurface. There can be one or more layers of liner between thesilicone-coated mineral wool and the interior surface. For example, inthis embodiment the silicone-coated mineral wool is in the form of aninsulation batt, with liners 232 (e.g., formed from paper) encasing themineral wool.

For example, loose-fill materials as described herein can be used inso-called “blow-in-blanket” applications, in which a netting or otherfabric encloses a cavity (e.g., in between wall studs) and a loose-fillinsulation material is disposed in the enclosed cavity. Such anembodiment is shown in FIG. 3, in which an exterior wall structure ofhouse 300 is shown in detail. Here, fabric 370 encloses a cavity 340partially defined by exterior surface 365 (here, a surface of asheathing). Loose-fill silicone-coated mineral wool 330 as describedherein is disposed in the cavity defined by the fabric. Loose-fillmaterials can also advantageously be used in so-called “open-blow”applications, for example in which a loose-fill material is disposedloosely on an attic floor or above a ceiling of a structure (e.g. alongan upward-facing surface, such as that described above with respect toFIG. 2).

Another aspect of the disclosure is an insulated structure (e.g., abuilding) having an interior surface and an exterior surface, and asilicone-coated mineral wool as described herein disposed in and atleast partially filling a cavity between the interior surface and theexterior surface. The cavity can be, e.g., in a wall of the structure, aceiling of the structure, or a floor of the structure. Such a structureis shown in FIG. 3, with the cavity being defined by the interiorsurface 360 (here, the surface of a wallboard) and the exterior surface365. In certain such embodiments, the cavity is substantially (e.g., atleast 90 vol %) filled by the loose-fill insulation material describedherein. And another aspect of the disclosure is an insulated cavityhaving a first surface and a second surface, and a silicone-coatedmineral wool as described herein disposed in between the first surfaceand the second surface.

Thus, the materials described herein can be used in insulating a varietyof structures by being disposed in a cavity therein.

Loose-fill insulation materials described herein can be installed withrelatively l densities, e.g., 0.25-0.510 lb/ft³. Loose-fill insulationmaterials described herein can be installed using conventional methods,e.g., by blowing. Conventional blowing methods can be used. For example,in certain embodiments, the loose-fill insulation can be provided withan additive to help promote adhesion in and/or prevent flyaway from thesite to be installed. For example, the loose-fill insulation can beblown with water (or some other evaporable liquid) to keep the materialin place during the blowing operation; the liquid can evaporate afterinstallation. In other embodiments, the additive can be an adhesive or abinder, e.g., to provide a more permanent adhesion. The person ofordinary skill in the art can use conventional materials in performingsuch methods.

The present inventors have observed a number of advantages from the useof a higher molecular weight silicone as described herein. For example,the mineral wool fibers can have high hydrophobicity. Moreover, thematerials can have a lower density as installed when the silicone usedto coat the fibers is of a higher molecular weight as described herein.This is especially important in the context of loose-fill insulation;such insulation is compressed for packaging, and the blowing process isused to decompress the material to a desired low density. As describedbelow, the present inventors have determined that use of a highermolecular weight silicone leads to a material that can be blown to alower density than a comparative material made with a lower molecularweight silicone. Without intending to be bound by theory, the inventorsposit that this is due to increased silicone coverage leading toincreased lubricity of the fibers, such that fibers can more easilyslide against one another, leading to increased expansion of thematerial during blowing, and thus a lower density as installed.

And, surprisingly, these benefits can be observed even when much lesssilicone is used in the coating operation. The present inventors, asdescribed below, determined that the performance of a material coatedwith high-molecular weight silicone can be better than a material coatedwith twice the amount of a lower molecular weight silicone.

In one set of experiments, glass fibers were coated while still hot(i.e., while falling from the spinning heads, temperature in the rangeof 285-430° C.) with an aqueous emulsion of silicone, then wereconventionally treated with a quaternary ammonium salt and an oil, thencompressed and packaged at about 8 lb/ft in conventional 31 lb bags. Thecontrol material was coated with a poly(dimethylsiloxane) having anumber-average molecular weight of about 13.7 kDa (“Low MW Silicone”),from an 0.7 wt % emulsion in water, to spray a total amount of 0.14 wt %silicone to the fibers. Three experimental coatings were performed usinga poly(dimethylsiloxane) having a nominal number-average molecularweight 62.7 kDa (“High MW Silicone 1”)). Coatings were performed usingthe same concentration of silicone as in the control (to apply the sameamount of silicone), as well as using half the concentration (to applyhalf the amount) and one-and-a-half times the concentration (to applyone-and-a-half times the amount). After different times of storage, thematerials were blown at a depth of a foot and the coverage at one footdepth per two 31-lb bags was measured; this value is shown both as thecoverage in square feet and as converted to a density (i.e., by theformula

${density} = {\frac{2 \times 31\mspace{14mu} {lb}}{1\mspace{14mu} {ft} \times {coverage}\mspace{14mu} {area}}{\text{)}.}}$

The table below provides density data for the control low-molecularweight-coated material and the three high-molecular weight-coatedmaterials (i.e. at 0.5, 1.0, and 1.5 times the coating amount ascompared to the control), as blown on the day of manufacture (0), and14, 36, 62 and 90 days after manufacture. The data demonstrate thatcoating with the high-molecular weight material leads to lowerdensities, even when using half the amount of silicone.

Time 0 days 14 days 35 days 62 days 90 days Control (low MW) 139.6 ft²147.9 ft² 151.9 ft² 144.9 ft² 159.8 ft² 0.444 lb/ft³ 0.419 lb/ft³ 0.408lb/ft³ 0.428 lb/ft³ 0.388 lb/ft³ 0.5x (high MW) 156.6 ft² 166.2 ft²165.3 ft² 152.0 ft² 167.1 ft² 0.396 lb/ft³ 0.373 lb/ft³ 0.375 lb/ft³0.408 lb/ft³ 0.371 lb/ft³ 1.0x (high MW) 152.7 ft² 162.7 ft² 145.2 ft²153.9 ft² 160.6 ft² 0.406 lb/ft³ 0.381 lb/ft³ 0.427 lb/ft³ 0.403 lb/ft³0.386 lb/ft³ 1.5x (high MW) — — 160.6 ft² — 159.8 ft² 0.386 lb/ft³ 0.388lb/ft³

Another set of experiments was performed to measure the molecular weightof a silicone coating on various silicone-coated mineral wools. Thecoatings were extracted using toluene (about 450 mL of solvent per about60 g mineral wool) overnight; after filtration and drying of thefiltrate via rotary evaporation, the residue was taken up in 10 mLtetrahydrofuran for permeation chromatography. The instrument wascalibrated using polystyrene standards; error bars shown are thestandard deviation of two injections of the same material on thechromatography system. In all cases, thermogravimetric analysis andtime-resolved infrared spectroscopy confirmed that the extractedmaterial was silicone. For experimental samples, the silicone emulsionused to coat the fibers was also measured by evaporation of the emulsionsolvent and taking up in tetrahydrofuran.

FIG. 1 is a bar graph showing molecular weight (Mp, mass of peak, Da) ofcoatings as measured by gel permeation chromatography (average of tworuns, calibration with polystyrene standards). Data for the first run ofeach sample are also provided in the table below:

Sample Mp Da Mn (Da) Mw (Da) Commercial sample 1 13000 17000 26000Commercial sample 2 ~600 — — Commercial sample 3 ~300 — — Low MWsilicone, Site C 14000 21000 42000 High MW silicone 1, Site A 57000 — —High MW silicone 1, Site B 60000 67000 112000 High MW silicone 2, SiteB, 18000 36000 77000 sample 1 17000 32000 61000 (two GPC runs shown)High MW silicone 2, Site B, 17000 28000 75000 sample 2 High MW silicone2, Site C 50000 81000 146000 Low MW silicone emulsion 14000 22000 41000High MW silicone 1 emulsion 63000 71000 102000 High MW silicone 2emulsion 82000 83000 119000

In FIG. 1, data are provided for three commercial materials, as well asfive experimental samples coated as described in the first set ofexperiments described above. High MW Silicone 1 was measured to have apeak molecular weight (Mp) of about 67 kDa; fiber material coatedtherewith from the first site and a second site (sites A and B) hadextracts having Mp values of about 58 kDa. High MW Silicone 2, apoly(dimethylsiloxane) silicone was measured to have an Mp value ofabout 62 kDa; fiber material coated therewith from a third site (site C)had an extract having a Mp value of about 50 kDa. At site B, however,the extract was only about 18 kDa. The Low MW Silicone was measured toprovide a peak molecular weight of about 14 kDa; the corresponding fibermaterial, made at site C had an extract having a peak molecular weightof about 10 kDa.

In another set of experiments, coated fibers were collected on a weeklybasis (collections seven days apart) from site B and site C, and fromtwo additional sites, site D and site E. During the multiweek set ofcollections, the silicone used was switched from a low molecular weightsilicone to one of the higher-molecular weight silicones. Two 31-lb bagsof product were collected at each collection; the material was blown ata depth of a foot and the coverage (in square feet) at one foot depthper two 31-lb bags was measured. Data are provided below.

Low MW silicone High MW silicone 2 Week coverage week coverage Site B 1148.3 9 158.1 2 152.4 10 156.2 3 156.5 11 155.6 4 155.5 12 155.6 5 15813 159.4 6 155.2 14 154.6 7 156.8 15 157 8 158.7 16 156.8 avg 155.2 avg156.7 Site C 1 152.1 7 161 2 155.53 8 158.96 3 156.55 9 158.37 4 157.0910 159.55 5 159.93 11 157.98 6 159.89 avg 156.8 avg 159.2 Low MWsilicone High MW silicone 1 Week coverage week coverage Site D 1 155.1 9155.1 2 153.9 10 161.3 3 151 11 153.2 4 148.2 12 155.6 5 154.5 13 154.26 146.8 14 153.8 7 149 15 154.3 8 147.4 16 157.5 avg 150.7 avg 155.6Site E 1 165.14 9 165.11 2 167.03 10 172.9 3 168.32 11 168.88 4 165.2 12160.53 5 163.7 13 163.03 6 158.09 14 154.2 7 159.5 15 161.05 8 153.24 16164.11 avg 162.5 avg 163.7

These weekly data points can be confounded by the fact that processcontrol is continually instituted in an effort to provide a producthaving a consistent coverage. To demonstrate effect at the time of thechange, ten days’ worth of data for Site C, High MW Silicone 2 areprovided with the materials being sampled and tested multiple times aday. The silicone was changed between the low MW silicone and the highMW silicone 2 between days 5 and 6. The average coverage over days 1-5was 157.6 ft², while the average coverage over days 6-10 was 163.8 ft².

Site C Site C Low MW Silicone High MW Silicone 2 Coverage, Coverage,ft²/62 lb ft²/62 lb Day Time bag Day Time bag 1  3:30 151.6 6  3:15166.9 1  5:30 152.6 6  9:10 159.8 1  7:28 152.9 6 11:35 167.9 1 12:50155.5 6 14:20 169.2 1 15:00 156.5 6 19:20 162.9 1 23:00 149.6 7  0:00167.9 2  2:30 150.2 7  4:24 162.9 2  4:45 151.1 7  9:40 160.9 2  8:00153.1 7 19:15 164.2 2 12:19 158.5 7 22:15 164.7 3  3:15 159.7 8  3:09161.4 3 10:00 164.2 8 12:15 161.1 3 17:00 167.6 8 17:00 162.5 3 23:45154.0 8 19:28 168.7 4  3:45 154.0 8 23:40 165.3 4  5:15 153.1 9  3:10160.5 4 15:25 156.2 9  9:00 159.9 4 19:28 155.8 9 12:30 161.6 5  0:00160.5 9 15:00 167.2 5  4:13 159.0 9 17:30 162.2 5  8:00 161.0 9 22:10162.7 5 11:10 171.4 10  1:05 164.4 5 14:40 163.7 10  3:35 168.5 5 19:17163.8 10  9:00 161.0 5 23:10 164.3 10 11:30 159.6 Low MW avg 157.6 HighMW avg 163.8

Moreover, it has been found that materials made with the high molecularweight silicone exhibit much less tendency to clump when being handledfor installation than the conventional materials made with low molecularweight silicones. This reduced clumping results in a number ofoperational advantages, including better uniformity of coverage, betterflow during installation, and fewer blockages of delivery machinery andthus fewer stoppages during installation of the material.

Various aspects of the disclosure are provided by the followingenumerated embodiments, which can be combined in any number and in anycombination that is not logically or technically inconsistent.

-   Embodiment 1. A method for making a silicone-coated mineral wool,    the method comprising:    -   providing a mineral wool comprising a collection of mineral wool        fibers;    -   applying to the mineral wool a solvent-borne coating composition        comprising a silicone, the silicone of the coating composition        having a number-average molecular weight of at least 25 kDa; and    -   allowing the solvent to evaporate to provide silicone-coated        mineral wool.-   Embodiment 2. The method according to embodiment 1, wherein the    mineral wool is a glass wool.-   Embodiment 3. The method according to embodiment 1, wherein the    mineral wool is a stone wool or a slag wool.-   Embodiment 4. The method according to any of embodiments 1-3,    wherein the median diameter of the fibers of the mineral wool (i.e.,    for each fiber, taken as the maximum distance across the fiber in a    direction perpendicular to the length of the fiber) is no more than    about 100 microns, e.g., no more than about 50 microns or even no    more than about 20 microns.-   Embodiment 5. The method according to any of embodiments 1-4,    wherein the median length of the collection of fibers is no more    than 500 mm, e.g., no more than 250 mm, or no more than 100 mm.-   Embodiment 6. The method according to any of embodiments 1-5,    wherein the mineral wool is at a temperature in range of 200-500° C.    when it is coated with the solvent-borne coating composition.-   Embodiment 7. The method according to any of embodiments 1-5,    wherein the mineral wool is at a temperature in the range of    200-465° C., e.g., in the range of 200-430° C., or 240-500° C., or    240-465° C., or 240-430° C., or 285-500° C., or 285-465° C., or    285-430° C. when it is coated with the solvent-borne coating    composition.-   Embodiment 8. The method according to any of embodiments 1-7,    wherein the mineral wool has a soak test pH in the range of 8 to 11    just before it is coated.-   Embodiment 9. The method according to any of embodiments 1-7,    wherein the mineral wool has a soak test pH in the range of 8.5-11,    e.g., in the range of 8.5-10.5, or 8.5-10, or 9-11, or 9-10.5, or    9-10.-   Embodiment 10. The method according to any of embodiments 1-9,    wherein the silicone of the coating composition has a number-average    molecular weight of at least 30 kDa.-   Embodiment 11. The method according to any of embodiments 1-9,    wherein the silicone of the coating composition has a number-average    molecular weight of at least 40 kDa.-   Embodiment 12. The method according to any of embodiments 1-9,    wherein the silicone of the coating composition has a number-average    molecular weight of at least 50 kDa.-   Embodiment 13. The method according to any of embodiments 1-9,    wherein the silicone of the coating composition has a number-average    molecular weight of at least 60 kDa.-   Embodiment 14. The method according to any of embodiments 1-9,    wherein the silicone of the coating composition has a number-average    molecular weight of at least 70 kDa.-   Embodiment 15. The method according to any of embodiments 1-14,    wherein the silicone is a polysiloxane.-   Embodiment 16. The method according to embodiment 15, wherein the    silicone is a poly(dimethylsiloxane).-   Embodiment 17. The method according to embodiment 15, wherein the    silicone is a polymer or copolymer of one or more of an    alkylsiloxane such as dimethylsiloxane and methylsiloxane; and    arylsiloxane such as phenylmethylsiloxane    2-phenylpropylmethylsiloxane, and phenylsiloxane; and a    functionalized siloxane such as 3-aminopropylmethylsiloxane.-   Embodiment 18. The method according to embodiment 17, wherein the    polymer or copolymer includes a functionalized siloxane such as    3-aminopropylmethylsiloxane.-   Embodiment 19, The method according to any of embodiments 1-18,    wherein the solvent of the solvent-borne coating composition is an    aqueous solvent, e.g., water.-   Embodiment 20. The method according to embodiment 19, wherein the    silicone is provided as an emulsion in the solvent.-   Embodiment 21. The method according to any of embodiments 1-20,    wherein the concentration of the silicone in the coating composition    is in the range of 0.01-5% by weight.-   Embodiment 22. The method according to any of embodiments 1-21,    wherein the rate of application of the coating composition to the    mineral wool is in the range of 0.1-10 mg silicone per gram mineral    wool.-   Embodiment 23. The method according to any of embodiments 1-22,    wherein the rate of application of the coating composition to the    mineral wool is in the range 0.1-5, e.g., in the range of 0.1-3, or    0.1-2, or 0.1-1, or 0.2-10, or 0.2-5, or 0.2-3, or 0.2-2, or 0.2-1,    or 0.5-10, or 0.5-5, or 0.5-3, or 0.5-2 mg silicone per gram mineral    wool.-   Embodiment 24. The method according to any of embodiments 1-23,    wherein the application of the solvent-borne coating composition to    the mineral wool lowers the temperature of the mineral wool to in    the range of 50° C. to 250° C.-   Embodiment 25. The method according to any of embodiments 1-24,    wherein the amount of silicone on the fibers after spraying is in    the range of 0.1-10 mg silicone per gram mineral wool.-   Embodiment 26. The method according to any of embodiments 1-24,    wherein the amount of silicone on the fibers after spraying is in    the range of 0.1-5, e.g., in the range of 0.1-3, or 0.1-2, or 0.1-1,    or 0.2-10, or 0.2-5, or 0.2-3, or 0.2-2, or 0.2-1, or 0.5-10, or    0.5-5, or 0.5-3, or 0.5-2 mg silicone per gram mineral wool.-   Embodiment 27. The method according to any of embodiments 1-26,    further comprising applying an effective amount of an antistatic    additive (e.g., a quaternary ammonium salt) to the mineral wool.-   Embodiment 28. The method according to any of embodiments 1-27,    further comprising applying a dedusting oil to the mineral wool in    an amount in the range of 0.4-4° /o by weight of the mineral wool.-   Embodiment 29. The method according to any of embodiments 1-28,    wherein the silicone-coated mineral wool is formed as an unbound    loose-fill material.-   Embodiment 30. The method according to any of embodiments 1-29,    further comprising compressing the silicone-coated mineral wool and    packaging it in a sealed container.-   Embodiment 31. A silicone-coated mineral wool comprising a mineral    wool comprising collection of mineral wool fibers having a silicone    coating comprising a silicone having a number average molecular    weight of at least 25 kDa.-   Embodiment 32. The silicone-coated mineral wool according to    embodiment 31, wherein the silicone has a number-average molecular    weight of at least 30 kDa.-   Embodiment 33. The silicone-coated mineral wool according to    embodiment 31, wherein the silicone has a number-average molecular    weight of at least 40 kDa.-   Embodiment 34. The silicone-coated mineral wool according to    embodiment 31, wherein the silicone has a number-average molecular    weight of at least 50 kDa.-   Embodiment 35. The silicone-coated mineral wool according to    embodiment 31, wherein the silicone has a number-average molecular    weight of at least 60 kDa.-   Embodiment 36. The silicone-coated mineral wool according to    embodiment 31, wherein the silicone has a number-average molecular    weight of at least 70 kDa.-   Embodiment 37. The silicone-coated mineral wool according to any of    embodiments 31-36, wherein the mineral wool is a glass wool.-   Embodiment 38. The silicone-coated mineral wool according to any of    embodiments 31-36, wherein the mineral wool is a stone wool or a    slag wool.-   Embodiment 39. The silicone-coated mineral wool according to any of    embodiments 31-38, wherein the median diameter of the fibers of the    mineral wool (i.e., for each fiber, taken as the maximum distance    across the fiber in a direction perpendicular to the length of the    fiber) is no more than about 100 microns, e.g., no more than about    50 microns or even no more than about 20 microns.-   Embodiment 40. The silicone-coated mineral wool according to any of    embodiments 31-39, wherein the median length of the collection of    fibers is no more than 500 mm, e.g., no more than 250 mm, or no more    than 100 mm.-   Embodiment 41. The silicone-coated mineral wool according to any of    embodiments 31-39, wherein the median length of the collection of    fibers is no more than 50 mm, e.g., no more than 25 mm, or no more    than 10 mm.-   Embodiment 42. The silicone-coated mineral wool according to any of    embodiments 31-40, wherein the silicone is a polysiloxane, e.g., a    poly(dimethylsiloxane).-   Embodiment 43. The silicone-coated mineral wool according to    embodiment 42, wherein the silicone is a polymer or copolymer of one    or more of an alkylsiloxane such as dimethylsiloxane and    methylsiloxane; and arylsiloxane such as phenylmethylsiloxane    2-phenylpropylmethylsiloxane, and phenylsiloxane; and a    functionalized siloxane such as 3-aminopropylmethylsiloxane.-   Embodiment 44. The silicone-coated mineral wool according to    embodiment 43, wherein the polymer or copolymer includes a    functionalized siloxane such as 3-aminopropylmethylsiloxane.-   Embodiment 45. The silicone-coated mineral wool according to any of    embodiments 31-44, wherein the amount of silicone on the fibers is    in the range of 0.1-10 mg silicone per gram mineral wool.-   Embodiment 46. The silicone-coated mineral wool according to any of    embodiments 31-44, wherein the amount of silicone on the fibers is    in the range of 0.1-10, e.g., in the range of 0.1-5, e.g., in the    range of 0.1-3, or 0.1-2, or 0.1-1, or 0.2-10, or 0.2-5, or 0.2-3,    or 0.2-2, or 0.2-1, or 0.5-10, or 0.5-5, or 0.5-3, or 0.5-2 mg    silicone per gram mineral wool.-   Embodiment 47. The silicone-coated mineral wool according to any of    embodiments 31-46, further comprising an effective amount of an    antistatic additive (e.g., a quaternary ammonium salt).-   Embodiment 48. The silicone-coated mineral wool according to any of    embodiments 31-47, further comprising a deducting oil on the mineral    wool in an amount in the range of 0.4-4% by weight of the mineral    wool.-   Embodiment 49. The silicone-coated mineral wool according to any of    embodiments 31-48, wherein the silicone-coated mineral wool is    formed as an unbound loose-fill material.-   Embodiment 50. The silicone-coated mineral wool according to any of    embodiments 31-49, compressed and packaged in a sealed container.-   Embodiment 51. The silicone-coated mineral wool according to any of    embodiments 31-50, made by a method according to any of embodiments    1-30.-   Embodiment 52. A silicone-coated mineral wool made by a method    according to any of embodiments 1-30.-   Embodiment 53. An insulated structure having an interior surface    (e.g., a surface of a wall, a ceiling, floor, an attic, a basement,    or another building surface), and a silicone-coated mineral wool    according to any of embodiments 31-52 disposed against the interior    surface.-   Embodiment 54. The insulated structure according to embodiment 53,    wherein the interior surface is an upward-facing surface of an attic    floor or above a ceiling of a structure.-   Embodiment 55. An insulated structure having an interior surface and    an exterior surface, and a silicone-coated mineral wool according to    any of embodiments 31-52 disposed in and at least partially filling    a cavity between the interior surface and the exterior surface.-   Embodiment 56. An insulated structure having an interior surface and    an exterior surface, and a silicone-coated mineral wool according to    any of embodiments 31-52 disposed in and substantially filling a    cavity between the interior surface and the exterior surface.-   Embodiment 57. An insulated cavity having an interior surface and an    exterior surface, and a silicone-coated mineral wool according to    any of embodiments 31-52 disposed in and a least partially filling    (e.g., substantially filling) the cavity between the interior    surface and the exterior surface.-   Embodiment 58. The insulated cavity or structure according to any of    embodiments 53-57, wherein the silicone-coated mineral wool has a    density of 0.25-0.510 lb/ft³.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the processes and devicesdescribed here without departing from the scope of the disclosure. Thus,it is intended that the present disclosure cover such modifications andvariations of this invention provided they come within the scope of theappended embodiments and their equivalents.

What is claimed is:
 1. A method for making a silicone-coated mineralwool, the method comprising: providing a mineral wool comprising acollection of mineral wool fibers; applying to the mineral wool asolvent-borne coating composition comprising a silicone, the silicone ofthe coating composition having a number-average molecular weight of atleast 25 kDa; and allowing the solvent to evaporate to providesilicone-coated mineral wool.
 2. The method according to claim 1,wherein the mineral wool is a glass wool.
 3. The method according toclaim 1, wherein the mineral wool is at a temperature in range of200-500° C. when it is coated with the solvent-borne coatingcomposition.
 4. The method according to claim 1, wherein the mineralwool has a soak test pH in the range of 8 to 11 just before it iscoated.
 5. The method according to claim 14, wherein the silicone of thecoating composition has a number-average molecular weight of at least 40kDa.
 6. The method according to claim 1, wherein the silicone of thecoating composition has a number-average molecular weight of at least 60kDa.
 7. The method according to claim 6, wherein the silicone is apoly(dimethylsiloxane).
 8. The method according to claim 6, wherein thesilicone is a polymer or copolymer of one or more of an alkylsiloxanesuch as dimethylsiloxane and methylsiloxane; and arylsiloxane such asphenylmethylsiloxane, 2-phenylpropylmethylsiloxane, and phenylsiloxane;and a functionalized siloxane such as 3-aminopropylmethylsiloxane. 9.The method according to claim 8, wherein the polymer or copolymerincludes a functionalized siloxane such as 3-aminopropylmethylsiloxane.10. The method according to claim 1, wherein the concentra the siliconein the coating composition is in the range of 0.01-5% by weight.
 11. Themethod according to claim 1, wherein the rate of application of thecoating composition to the mineral wool is in the range of 0.1-10 mgsilicone per gram mineral wool.
 12. The method according to claim 1,wherein the application of the solvent-borne coating composition to themineral wool lowers the temperature of the mineral wool to in the rangeof 50° C. to 250° C.
 13. The method according to claim 1, wherein theamount of silicone on the fibers after spraying is in the range of0.1-10 mg silicone per gram mineral wool.
 14. The method according toclaim 1, further comprising applying an effective amount of anantistatic additive to the mineral wool, and/or a dedusting oil to themineral wool in an amount in the range of 0.4-4% by weight of themineral wool.
 15. The method according to claim 1, wherein thesilicone-coated mineral wool is formed as an unbound loose-fillmaterial.
 16. A silicone-coated mineral wool comprising a mineral woolcomprising collection of mineral wool fibers having a silicone coatingcomprising a silicone having a number average molecular weight of atleast 25 kDa.
 17. The silicone-coated mineral wool according to claim16, wherein the silicone has a number-average molecular weight of atleast 40 kDa.
 18. An insulated structure having an interior surface, anda silicone-coated mineral wool according to claim 16 disposed againstthe interior surface.
 19. An insulated structure having an interiorsurface and an exterior surface, and a silicone-coated mineral woolaccording to claim 16 disposed in and at least partially filling acavity between the interior surface and the exterior surface.
 20. Aninsulated cavity having an interior surface and an exterior surface, anda silicone-coated mineral wool according to claim 16 disposed in and aleast partially filling the cavity between the interior surface and theexterior surface.